Technical Field
The disclosure relates in general to an oscillator, and more particularly to a method and a circuitry for generating a trigger signal based on an oscillation signal and associated non-transitory computer program product.
Description of the Related Art
In electronics and especially synchronous digital circuits, a clock signal oscillating between a high level state and a low level state is essential. FIG. 1 is a schematic diagram illustrating a crystal oscillator used in a digital circuit. Crystal oscillators 11 are widely used for generating clock signals (CLK). A chip 10 of the digital circuit 1 is synchronized by the clock signal (CLK).
The requirement for low power (hereinafter, LP) consumption has been growing at an exponential rate, and many electronic devices provide a power saving mode (for example, standby mode, sleep mode etc.). In order to ensure the electronic product can swiftly change from the power saving mode to a normal mode, the crystal oscillator 11 continues to operate even if the chip 10 is disabled in the power saving mode. However, power assumption of the crystal oscillator 11 is relatively high and should not be neglected.
Since the crystal oscillators consume significant power, on-chip oscillators (for example, LP oscillator) are designed to replace the crystal oscillators in the power saving mode. Although the on-chip oscillators consume less power than the crystal oscillator, frequency of the LP oscillator is not as accurate as frequency of the crystal oscillator. That is to say, the LP oscillator is not suitable for application having tighter frequency tolerances. Consequentially, selecting an oscillator to meet both the requirement of accuracy and low power consumption becomes a dilemma.